Plasma-Supported Coal Combustion Modeling and Full-Scale Trials

Abstract

Plasma-supported solid fuel combustion is a promising technology for use in thermal power plants (TPPs). Development of this technology comprises two main steps. The first is the execution of a numerical simulation and the second involves full-scale trials of plasma-supported coal combus- tion through plasma-fuel systems (PFS) mounted on a TPP boiler. For both the numerical simulation and the full-scale trials, the 200 MW boiler at Gusinoozersk TPP (Russia) was selected. The optimization of the combustion of low-rank coals using plasma technology is described, together with the potential of this technology for the general optimization of the coal burning process. Numerical simulation and full-scale trials have enabled technological recommendations for improvement of existing conventional TPP to be made. PFS have been tested for plasma start-up and flame stabilization at 27 TPP boilers in various countries. Steam-productivity of these boilers varied between 75-670 t/h (TPH), with each boiler equipped with different types of pulverized coal burner. During PFS testing, coals of all ranks (brown, bituminous, anthracite and their mixtures) were used, the volatile content of which varied from 4% to 50%; ash - from 15% to 48% and calorific values - from 6,700 to 25,100 kJ/kg. In summary, it is concluded that the developed and industrially tested PFS improve coal combustion efficiency and decrease harmful emission from pulverized coal-fired TPP.